Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH 5/6]: powerpc/cell spidernet bottom half | Date | Sat, 19 Aug 2006 01:03:04 +0200 |
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On Saturday 19 August 2006 00:26, Linas Vepstas wrote: > The recent set of low-waterark patches for the spider result in a > significant amount of computing being done in an interrupt context. > This patch moves this to a "bottom half" aka work queue, so that > the code runs in a normal kernel context. Curiously, this seems to > result in a performance boost of about 5% for large packets.
I guess this one still needs some work. We already have a bottom half mechanism in the network layer, using the NAPI poll function that is strongly serialized.
Linas, you wrote that you have tried doing the TX descriptor cleanup in dev->poll(), but I think you missed the point that this function needs should then be scheduled whenever necessary.
This seems a little strange, but I think what we need to do is in the low-watermark interrupt call netif_rx_schedule(netdev) in order to arrange for the ->poll function to be called in the next softirq.
Someone should probably document that in Documentation/networking/NAPI_HOWTO.txt, I might end up doing that once we get it right for spidernet.
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